2004 August Great West Cyclone
The 2004 Great West Cyclone(also known as Cyclone Thirteen or Cyclone Maikerū)was the most intense Cyclone by pressure in the Lucarius Pacific, and most intense landfalling Cyclone in the whole world at 867 mbar. In addition, it was the second costliest Lucarius Pacific Cyclone with $125.7 billion and the overall deadliest Lucarius Pacific Cyclone with 2,219 deaths. This Cyclone was the first in history to be over more than 10 different states in the US while Tropical or Subtropical in any basin(California, Nevada, Utah, Colorado, Kansas, Nebraska, Iowa, Minnesota, Illinois, Ohio, West Virginia, Maryland, Pennsylvania and New York). It also became the first and only Category 8 Intense Tropical Cyclone(LCCS)at a higher latitude than 20° North. It was also the first Sub-900 mbar Cyclone observed in the month of August, and the earliest overall until Cyclone Nine in 2009 did so in May. Meteorological History Formation and Rapid Intensification On August 3, the LCA began to monitor a broad Tropical Wave near Southern Mexico. The Invest would continue developing slowly as it headed generally Northwest. On August 5, many vortices began to interact and a dominant one began to take shape, one of which branched off to become Severe Tropical Storm Fourteen a week forward, the other two becoming elongated rainbands. On August 7 at 0:00 MST, the LCA declared Tropical Depression Thirteen; South of Manzanillo. Northwestern motion continued throughout the next few days. That same day, the LCA declared the system a Tropical Storm due to a recon flight showing results indicative of Gale force winds. The storm accelerated into more favorable conditions; with strengthening accelerating as well. Late on August 8 shortly after being declared a Tropical Cyclone almost parallel in latitude with Tepic, cloud tops began to begin a short warming phase, and an eye appear just 12 hours later. It was at this point that the original rapid intensification phase was thought to have begun. However, gradual intensification was ruled and the 20 mph strengthening was thought to be an anomaly. Despite this on August 9, Thirteen began to rapidly cool it’s Cloud Tops and a visibly symmetric eye was becoming present. Over the course of August 10-13 while paralleling the coast of Baja California, short bursts of intensification of anywhere from 5-15 mph per 6 hour interval occurred. On August 14, the Cyclone had reached it‘s initial peak of 215 mph and 874 mbar. Several Cyclone Warnings began ranging from Los Angeles to Tijuana. Initial Landfall and Resurgence Cyclone Thirteen held it’s extreme stature for the next 24 hours as it approached land. Over 2 million people were ordered to evacuate in San Diego and Los Angeles and a State of Emergency was declared for anyone within a 250 mile radius of the two cities. On August 16 at about 6:30 MST, the LCA released a special advisory detailing that the storm had made landfall within Los Angeles coastal limits. The cyclone began an abrupt period of weakening due to land interaction despite remaining over the 170 mph minimal for Category 7 status on the LCCS. Due to 3 various low pressure systems surrounding it, the cyclone began an irratic track Southeastward where it would eventually reunite with Water early on August 19. The still extremely intense cyclone began another short period of Rapid Intensification over the next 36 hours; strengthening from 175 mph to 205 mph in this time period. Baja Landfall and Weakening Tijuana and several areas surrounding the city issued their own State of Emergency. Despite this, it was estimatd that only slightly less than 1 million residents had evacuated due to unawareness, traffic pileups or underestimation of the storms intensity. On August 21, the storm made landfall about 7 miles South of Tijuana‘s city limits. Cyclone Thirteen, contrary to forecasts, held it’s intensity over Baja California, only weakening to 185 mph. However, despite resurfacing over waters(Which had over 41°C SSTs), the Cyclone underwent a short eyewall replacement cycle, weakening it further to 165 mph over the course of August 23. Second Explosive Intensification and Final Landfall Following the eyewall replacement cycle, the Cyclone executed yet another erratic loop; causing it to remain somewhat stationary in an immensely favorable environment. It executed it’s third, final and most explosive period of rapid intensification starting on August 28. The dreadful Cyclone began another Northward movement , sparking yet another slew of Emergencies, Evacuations and Warnings in Northern Mexico and Arizona. On August 30, the cyclone reached it’s peak intensity of 230 mph and 867 mbar, the most intense pressure on record; besting Cyclone Ten of the previous year(869 mbar). The next day, the cyclone made landfall at that intensity and accelerated North. Over 3 million people were evacuated in Northern Mexico and Arizona(mostly in Phoenix). Traversing the Southwest and Coloradan Mountains The cyclone began a generally Northward track; fluctuating between a 15-25 mph movement speed throughout this period. Overall, the storm held a positive eye temperature until September 12 while over land despite mountainous terrain of the Rocky Mountains. Overall, about 300,000 evacuees resulted in Nevada, Utah and Colorado. This was the first Tropical Cyclone to traverse all three states until 2 other cyclones would do so(Nine of 2009 and Breloom of 2018). Restrengthening and Acceleration towards Great Lakes The cyclone started to slow it’s weakening while it crossed the lesser elevations of the Mid-Western US. However, conditions became anomalously favorable as it began to accelerate from 10-15 mph to 20-27 mph towards the Great Lakes reigon. The cyclone strengthened from 75 mph to 100 mph, the only occurrence worldwide on record. As the storm entered Michigan, some Subtropical charateristics took form, but overall the storm was said to have remained tropical. Stalling over Ohio and Subtropical Transition Due to a slightly stronger Low Pressure system over Canada to it’s Northwest, the cyclone dipped into Ohio on September 16. For the third time, the storm became stuck in a mess of 3-4 Low Pressure systems, causing more erratic movements. This erratic movement created temporary weakening conditions to a Category 1 Cyclone from Category 2. Over the course of September 18-22, Cyclone Thirteen would begin to lose more and more topicality, eventually having it’s maximum winds spread out as it headed west while at a stalemate with an impeding cold front. Despite this, barcelonic forcing began to take over and allowed the system to shortly strengthen to Category 2 status once again. However, as it begun it‘s Eastward motion again, it’s final weakening phase ensued as wind shear picked up the more to the East it went. The badly sheared cyclone would shed more than half of it’s previous mass and be officially classified as a Subtropical Cyclone in the process(some debate that it had done so in previous advisories). Acceleration towards New England and Demise Eventually, the storm came to an abrupt stop over the Western Maryland Panhandle, continuing to weaken on September 25. The barely Subtropical Cyclone then shifted directions Northward due to the presence of it’s associated front’s influence pulling it Northward. The cyclone as a result of incredibly high shear and the high movement speed; collapsed and began to succumb to a frontal nature. Due to this, it was finally declared an Extratropical Cyclone on September 27. The now Extratropical Cyclone would continue it’s North-Northeastern track into Canada before being torn apart by a stronger system on September 30 over Eastern Canada. Impact California Baja California and Northern Mexico Nevada Utah Colorado Midwestern US Kansas Nebraska Iowa Great Lakes Region Minnesota Michigan Indiana Illinois Ohio Northeastern US and Canada Maryland West Virginia Pennsylvania New York New Hampshire and Vermont Canada Other Areas Arizona Indiana Kentucky Virginia North Carolina Records Category:Cyclones Category:Past Storms Category:Lucarius